Comminuting apparatus



United States Patent COMMINUTING APPARATUS Thomas Cropper Ryley Shepherd, .Ross-on-Wye, England Application October 3, 1956, Serial'No. 613,757 Claims priority, application Great Britain October 7, 1955 3 Claims. (Cl. 241-46) This'inven'tion concerns comminuting apparatus comprising a shaft to drive a comminuter and a seal around the shaft to reduce or prevent ingress of material delivered to theapparatus to a shaft-driving means e. g. an electric motor. Hitherto it has been found that material delivered to the apparatus comes into contact with the seal, and that certain classes of material rapidly destroy the 'seal. For example, when comminuting pairings from vegetables it is commonly found that earth (e. g. sand particles) are delivered to the comminuter together with the pairings and that the sand finds its way into the seal so that the life of the seal is relatively short.

A practical application of the present invention will now be described, by way of example only, with reference to the accompanying drawing which illustrates in elevation, and mainly in section, an apparatus in accordance with this invention.

Referring to the drawing: the apparatus is illustrated as fitted to the outlet of a kitchen sink, the bottom of which is indicated by the reference numeral 1, the bottom being provided, in conventional manner, with an outlet 2 which may be closed by a plug 3. When the plug is removed or opened material in the sink passes through the opening 2 and into the comminuting apparatus, which is generally indicated by the reference numeral 4.

The apparatus 4 comprises a casing 5 into which the waste material from the sink 1 drops from above. Immediately beneath the receiving chamber 5 is a toothed ring 6 and a rotor 7 mounted on a shaft 8 which is The object of this invention is the provision of animproved construction of apparatus in which maintenance and repair is reduced compared with known machines. I More particularly an object of the invention is to ensu're that the life of the seal is longer than with existing comminuting apparatus.

Another object is to provide that the seal shall not be subjected to excessive wear.

Yet a further object of the invention resides in the provision of means for preventing or reducing ingress of destructive material to the seal.

An object of the invention-resides in using waterto flush the seal and to prevent ingress of material to the" seal and of utilising the water to wash out the apparatus. The present invention is characterised in that there is provided means to supply water to the seal to carry material away from the seal. Yet a further object of the invention is the provision of a water supply for seal flushing at a relatively great pressure. l

It is yet another object of the invention to provide in a simple and effective manner that the pressure of the water for preventing material entering the seal and for washing the apparatus shall be raised within the apparatus.

Finally-it is an objectofthe invention to ensure that 1 when' the apparatus is in use the supply of water-is maintained for the purposes-indicated. r a Aparticular advantage of theinvention results if the water'is directed-overthe' seal and is discharged from the driven by an electric motor 9.

The shaft 8 is supported in a diaphragm member 10 which defines the bottom of a discharge chamber 11 lying immediately beneath the rotor 7. The chamber 11 has cylindrical walls 12 and a discharge outlet 13.

The bottom member 10 constitutes a housing for a seal 14 which surrounds the shaft 8 and is provided to reduce ingress of material delivered to the apparatus (including water delivered with the material to be comminuted to the electric motor 9. Ithas been found that in previous comminuting apparatus material delivered to the apparatus coming into contact with the shaft seal had an excessive abrading action on the seal with the result that its effective life was short. More particularly this is found when comminuting vegetable pairings which are commonly coated with earth particles, sand and the like. In order to reduce excessive wear of the seal 14 a radial channel 15 is provided in the member 10, the channel leading into a space 16 surrounding the seal 14. A water supply pipe 17 is connected to the member 10 so that water may pass along the channel 15 into the space 16 and the flow of water is controlled by a valve 18, the operation of which is determined by the electric motor 9, the latter being coupled to the valve 18, as at 20. It is arranged that when the motor 9 is started the valve 18 is opened and thereseal to flush the apparatus beneath said rotor. It may be I arranged that the water is supplied to a housing for the seal and is discharged therefrom .in whichevent it is preferred that said-means is arranged to direct part of the water axially from the seal housing into a chamber in the rotor and to discharge water under centrifugal force, due: to rotation of the rotor, through a narrow gap' between said housing and the'rotor With this arrangement it may be arranged that the water discharged from the said narrow gap will wash "theundersurface of the rotor, the cylindrical wall of the discharge chamber and the bottom member ofthe chamber after the comminuting operation has been completed so that theentire discharge chamb'er is left in a clean and wholesomelconditi on I 'l sit-nut; 2.

fore water is delivered to the space 16. The supply of water will be at an adequate pressure to ensure a good flow of water through the space 16 as later described.

The rotor 7 comprises a disc portion 21 which carries a plurality of hollow breakers, generally indicated at 22. The breakers 22 co-act with the teeth 23 of the ring 6 to comminute material dropped into the casing 5, the comminuted material passing between the teeth and between the peripheral edge of the rotor and the teeth into the discharge chamber 11 and being carried away from-said chamber through the outlet 13 as more fully described hereinafter.

An'axial passageway 24 is formed in the hub of the rotor 7, the passageway 24 being directly opposite to.

the space 16which extends through the top of the member 10. The passageway 24 communicates with the interior of the hollow breakers 22 at the inner radial extremities of the breakers.

The rotor 7 is mounted on the shaft 8 so that the lower edge of the rotor is spaced by a small amount from the topmost part of the member 10, a narrow annular gap 25 being defined between the rotor and the member 10.

With thearrangement described water supplied to the space 16 passes axially upwardly into the passage 24 and from thence into the hollow breakers 22 for purposes which will later be referred to. Some of the water passing from the space 16 to the axial passageway 24 discharges throughthe narrow gap and some of the Water 3 subjected to centrifugal pressure within the axial passageway 24 is forced under considerable pressure through s s p- It will be appreciated that whenthejcorhminuting apparatus is bfought'i ntouse and the meters is started water will be supplied to the space -16faiid 'atter flowing around the seal 14 passes, in part, through the narrow gap 25. Since material destructive t'othe" seal 14 can only enter the seal housing through said ga and at all times while the apparatus is in operation a stream of water is being ejected through said gap the stream of ejected water effectively prevents the admission of said material to the seal housing.

The water ejected through the gap 25 is directed over the undersurface of the rotor 7 and against the wall 12 of the chamber ll. Moreover, the water will flow bver the upper surface of the member 10. The gap 25 is atthe topmost part of the bottom member 10 and said surface slopes downwardly, as at 26, uniformly from the top of the member 10 towards the outlet 13, so that the latter is at the lowest part of the member 10. The water is ejected from the gap 25 near the top of the chamber 11 i. e. against the undersurface of the rotor 7 and towards the top of the wall 12 which 'isbeneath the rotor and above the topmost part of the discharge outlet 13 with the etiect that all of the water flows downwardly towards the outlet. The entire surface'of the chamber 11 is flushed'out by the water ejected from the gap 25 and comminuted material within the chamber 11 is carried by the stream of water to the outlet 13 and discharged therethrough so that after each operation of the comminuting apparatus the chamber 11 will be left in a clean and wholesome condition. This is particularly important since if particles of food and other material remain lodged in the apparatus unpleasant odours will occur and the general cleanliness will be seriously impared.

Concerning the water which is supplied to the hollow breakers 22: the wall 27 at the outer radial extremity of each breaker is provided with a pair of vertically spaced nozzles 28, the nozzles being directed toward the teeth 23 of the ring 6. The upper of the pair of nozzles 28 a. his to be understood that at least a pair of. diametrically opposed breakers 22 are provided on the rotors 7 and each rotor is formed with an inclined wall 29 as described and each wall is provided with a nozzle 30. As a result at least two upwardly directed jets of water are produced and it is arranged that these jets converge at, or near to, the axis a.

Certain loose materials when wet form a coherent mass which if it rests on the rotor 7 can not be pulverised. On the other hand if the mass is carried outwardly it will clogthe teeth 23 and, becoming lodged between the breakers 22 and the ring of teeth 6, will seriously impair the rotation of the rotor. Used tea leaves which in catering establishments, for instance, are commonly discharged into a comminuting apparatus in relatively large quantities is an example of such a material. Unless steps are taken to prevent these occurrences the apparatus may be brought to a standstill and the motor 9 burnt out. The upwardly directed jets of water leaving the nozzles 30 ensure that when such a mass is dropped through the opening 2 it is held in partial and temporary suspension and gradually passes between the breakers 22 and the ring of teeth 6 where it is acted upon and pulverised.

The jetsof Water from the nozzles 30 are directed towards the opposite side of the wall of the casing 5 and will ricochet therefrom in an upward direction to wash the wall and top of casing 5 and ensure that all material is close to the top of the ring of teeth. Water under centrifugal pressure is discharged from the nozzles 28 in an outward radial direction to impinge on the teeth 23. The teeth "are of increasing depth in the downward direction. The water impinging on the teeth will was-h comminuted material from between the teeth and this material will be carried downwardly into the chamber 11, the increasing depth of the teeth assisting in this operation since once the material has become dislodged it will readily travel downwardly. The upper jet of water will impinge on the top part of the ring of teeth and part of the impinging stream will be directed upwardly to above the ring 6. Accordingly material lying upon the topof the ring ofteeth is dislodged and is further acted upon by the breakers.

With the arrangement described the jets of water discharging from the nozzles 28 under centrifugal pressure prevent clogging of material between the teeth and the rotor and wash comminuted material awayfrorn between the teeth and carry it into the chamber 11 where it will bedealt with in the manner described above. It is thereby ensured that the teeth are maintained in a clean and wholesome condition at the end of each comminuting operation. Furthermore, the jets of water will apply material to the teeth and assist in the comminuting operation. It will'be observed that each hollow breaker 22 is formed, at its inner radial extremity, with a wall 29 which: is obliquely inclined with respect to the axis of rotation of the shaft 8, the axis ofrotation being indicated atva. Extending substantially normally through thewall29 is a nozzle 30 sothat water under pressure. will be directed upwardly of the rotor towardsthe axis is carried downwardly past the rotor.

To sum up: firstly, the jets of water from the nozzle 30 maintain material such as tea leaves which tend to clog the rotor 7 in partial suspension and ensure that the mass is gradually fed to between the breakers 22 and the teeth 23 and they also act to wash down the casingv 5 so that it is left in a clean and wholesome condition. Secondly, the jets from the nozzles 28 act to clean and clear the teeth 23 and to carry material downwardly into the chamber 11 as well as ensuring that clogging of material on the top of the ring 6 is prevented. Finally, the water ejected from the gap 25-Washes the chamber 11 and carries comminuted material towards the outlet 13 from which it is discharged.

The arrangement described in which the comminuting apparatus is atfixed to a sink the material to be treated is carried into the apparatus with water from the sink. However, in industrial kitchens, such as in catering establishments, it is arranged that the comminuted material is introduced into a bowl which is not supplied. with water from the main. In such an arrangement a supply of water to flush material from the sink into the comminuting apparatus is provided by a branch pipe. which is connected to a junction 34 on the outlet side of the valve 18. Accordingly, when the apparatus is started and valve 18 is opened, water is supplied, as described above, to the channel 15 and through junction 34 and the branch pipe to the sink bowl so that the ma? terial to be comminuted is delivered to the apparatus 1 from the sink bowl with a stream of water.

It will be appreciated that the water to the sink bowl is only supplied when the comminuting apparatus isnin operation. The junction 34 is blocked off when not required to supply water as just described. a

In an alternative arrangement utilising water thrown upwardly from the rotor to impinge on the material to be comminuted whereby it is prevented from impaction a jet (or jets) of water is (or are) directed down onto the rotor (e. g. from a nozzle in the casing 5) and will ricochet upwardly therefrom and at the same time will be thrown outwardly (thus washing the wall of easing 5) by centrifugal force due to rotation of rotor 7.

In yet another arrangement jets of water are directed centrifugally of the rotor in an outwardly, substantially horizontal direction against thewall of easing 5 above toothed ring 6 and part of the water will ricochet therefrom, being directed in an upward and inward direc- .5 tion (as in the arrangement first described) and will reduce or prevent impaction as well as washing down casing 5.

I claim:

1. A comminuting apparatus comprising a housing ineluding a diaphragm portion and defining a comminuting chamber at one side of said diaphragm portion, comminuting means disposed within said chamber and including a rotor, a shaft extending through said diaphragm portion and drivingly connected to said rotor, motor means operatively connected to said shaft, said diaphragm portion and said rotor cooperating to define a seal chamber through which said shaft extends and said diaphragm portion and said rotor cooperating to define an opening between said rotor and said diaphragm portion providing the sole communication between said comminuting chamber and said seal chamber, sealing means mounted in said seal chamber for preventing movement of material along said shaft past said sealing means and toward said motor means, means for supplying water to said seal chamber to provide for flow of water through said seal chamber and outwardly through said opening to said comminuting chamber, and means providing a discharge outlet communicating with said comminuting chamber.

2. A comminuting apparatus as defined in claim 1, wherein said opening is annular in shape.

3. A comminuting apparatus as defined in claim 1, wherein said diaphragm portion slopes downwardly away from said opening and said discharge outlet communicates with said comminuting chamber below said opening.

References Cited in the file of this patent UNITED STATES PATENTS 2,027,015 Bell Jan. 7, 1936 2,282,883 Powers May 12, 1942 2,562,736 Powers July 31, 1951 2,766,943 Lockley et a1. Oct. 16, 1956 

